Some considerations about forage crops "Pastures”

In the study of agriculture and livestock there is a great diversity of opinions, especially with regard to pastures, making it clear to everyone that it is a crop and deserves the agronomic management that any productive plant needs. In this particular case we had a talk with the engineer Chompe a few weeks ago about certain aspects related to pastures and that we will leave reflected in this article.

Let's start by pointing out that, according to what has been discussed, in any livestock farming system it should be borne in mind that we work with a dynamic and biotic complex, in pastures this system is constituted by soil, plant, animal and man as the manager of the complex, this in order to manage the forage resource in the best possible way, this being the most economical and abundant source of feed for grazing animals. Pasture management has been the object of study in animal production, with the purpose of offering better nutritional quality to grazing animals every day, but there are many factors that intervene in the process of development and growth of the plant until it is consumed. Environmental, genetic, morphological and agronomic management factors are key to harvest a pasture with good nutritional values, defining it as of good quality for the physiological state of the animal that is consuming it.

In this sense Sánchez (2007), indicates that the management of pastures should be oriented to the production of large quantities of biomass, in turn this should be of good nutritional value and usable by animals, all this, framed within a concept of persistence of pastures and sustainable agriculture. The above is acceptable, but the species of grass must have an adaptation to the environment, this as a limiting factor of plant production, temperature is a limiting factor of importance in the production of pasture, this being one of the main ones to take into account when establishing a pasture or fodder. Herrera, (2005), indicates that it is necessary to sow productive pastures, but well adapted to the climate where they will be established.

On the other hand, Dávila (2005), mentions that each grass has its particular morphology, so the management of each forage species is different, hence the knowledge of each species that makes up the mixture in order to maintain an optimal production point. Other limiting factors of pasture production in quality and quantity are the management to which the pasture is subjected, days of occupation by the animal, irrigation and fertilizations. In addition to harvest age and leaf-stem ratio, even the species of grass and its use at the time of harvest could be limiting. To achieve a good management of the paddocks, soil sampling for their respective analysis, soil preparation, implement irrigation and drainage system, fertilizer application at the time of planting, associate with forage legumes, harvest at the optimal time of pre-flowering and avoid overgrazing are important practices.

In this same vein, it can be mentioned that the soil with its physical and chemical properties affect the growth, composition and persistence of grasses, it also has an indirect effect on reproduction, composition, metabolism and animal production, to the east directly affect the production of grass. The plant has an effect on the physical properties of the soil, in terms of structure, porosity and water retention, as well as on chemical properties, such as organic matter content and pH. As it has a direct impact on the animal, in its reproduction and production, milk production and weight gain depend on the quantity and quality of the grass eaten, which depends on its composition and digestibility.

The animal when grazing indirectly depletes the nutrient reserves in the soil, although research indicates that 75% of the N, 80% P and 85% of the K contained in the grass are returned by the animal through the excretions in the paddock, as it has been recorded that undergrazing increases the seeding, number of leaves, lignification and root weight in certain species of grass, the bovine by being selective can harm and favor others, a little consumed species can become dominant and in turn a food coarse, low in protein and high in fiber.

Finally, dear readers, it can be said that the relationships in the grassland ecosystem, as well as the limiting factors of grass development should be under investigation, grass under exceptional management is an ideal and quality food, the use of concentrates as a substitute for pastures or forages is uneconomical, every day more species of pastures are conditioned to previously unsuitable conditions, biotechnology takes a giant step, but it is on the part of the producer to consider pastures one more crop that should be treated and managed like any other of exploitation.